The children of women given labetalol and methyldopa to treat high blood pressure during pregnancy may be at risk of developmental problems, research suggests.
The study, conducted by experts in the Netherlands, has not found definitive proof that the drugs cause problems in children, but it has found a possible link.
The medicines are commonly given, even when women have only mild to moderate cases of high blood pressure.
Researchers studied the records of 4,000 patients from 12 hospitals, all of whom had suffered high blood pressure caused or made worse by pregnancy.
They were able to study the effects of the drugs on 202 children aged between four and 10, to see how they may have affected their IQ, concentration, motor development and behaviour.
The researchers found that those who had been exposed to labetalol were twice as likely to have attention deficit hyperactivity disorder (ADHD) than those exposed to methyldopa, and four times more likely than if their mothers had simply been told to rest.
Methyldopa also returned some negative results, with youngsters exposed to it having more sleeping problems. Tests examining other aspects of development did not show either of the drugs to be worse than the other.
However, the researchers said more work needed to be done to confirm a link between the drugs and development in babies, as the current conclusions were based around a hypothesis.
The study was published in BJOG: An International Journal of Obstetrics and Gynaecology.
Copyright Press Association 2010
BJOG: An International Journal of Obstetrics and Gynaecology